MCP: instance-scoped collection read/write (insert_record/query_records/list_collections)

[serge-ivo]

Gap found while wiring the lead-finder (2026-08-02). query_records/list_collections/insert_record are template(agent)-scoped only — calling them with an instance id returns `{"error":"Agent not found"}`. So there is no MCP path to read or write a subscribed instance's collections, even though the console does it via `/v1/instances/:id/collections/*`.

Why it matters

• An external process (e.g. the lead-finder's standalone sweep Worker, or Coder) cannot push records into an instance collection via MCP — it must hand-roll auth against the REST route. That's the difference between "call an MCP tool" and "write bespoke plumbing + a token."
• Agents/automation can't inspect a live instance's data programmatically (the /data tab is human-only).

Ask

Add instance-scoped collection tools to the MCP server (or make the existing ones accept an instance id):

• list_instance_collections(instance_id)
• query_instance_records(instance_id, collection, where?, limit?, order_by?)
• insert_instance_record(instance_id, collection, data) (respect the collection's unique/dedup constraints)
• Owner-scoped + audited like the other instance MCP tools; gate writes behind the write scope.

Acceptance

• An owner can read/insert into /v1/instances/:id/collections/leads via MCP.
• The lead-finder sweep can sync leads into its PAGS instance collection by calling MCP instead of bespoke REST auth.

Motivating case: #58 program / the small-business-website-lead-finder agent.